The mass of winding streets between the Grand Bazaar and the Golden Horn contains many old Ottoman commercial buildings, or hans. Historically, the most important of these was the Büyük Valide Han, commissioned in the 17th century by Valide (queen mother) Kösem Sultan; it was used to store goods coming off ships anchored in the Golden Horn and as a kervansaray, or hotel, for traveling merchants. At the entrance, note the enormous iron-plated doors, which were—and still are—closed at night for security. The han continues to be a working building, occupied mainly by textile wholesalers and small sewing workshops, but visitors are welcome to have a look around. Opposite the Büyük Valide Han, just a bit farther down the hill, are two other large hans, the Büyük Yeni Han and Küçük Yeni Han, both dating to the 18th century. In the northwest corner of the Büyük Valide Han, a crumbling old stone staircase leads up to the roof, which offers a fabulous view of the
city. If you wish to venture up, find the caretaker, Mehdi Bey (who is usually on the northwest corner of the second floor, near the room where he lives), and offer him a small tip to unlock the door for you. Note that climbing up to the roof is at your own risk, as there aren't any railings on the roof.